Art and mechanism for drawing hollow cylindrical metal bodies



C. B. HIGGINS.

ART AND MECHANISM FOR DRAWING HOLLOW CYLINDRICAL METAL BODIES.

' APPLICATION FILED 05cm, 1920.

1,422,974., Patented July 18; 1922.

3 SHEETS-SHEET I.

I N VEN TOR. K /FFQZZ ,5 Maw/7a C. B. HIGGINS.

ART AND MECHANISM FOR DRAWING HOLLOW CYLINDRICAL METAL BODIES.

APPLICATION FILED DEC-27, I920. 1 4293743 Patented July 18, 1922.

3 SHEE'I SSHEET 2.

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C. B. HIGGINS.

ART AND MECHANISMFOR DRAWING H0 CYLlNDRlCAL METAL BODIES.

APPLICATION FILED 7. 1920.

1 422374 Patented July 18 22.

' 3 sums INVENTOR. -cZ/F%efl i5. /V/"//Xf BY M a d ATTORNEY.

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CLIFFORD B. HIGGINS, OF DETROIT, MICHIGAN, ASSIGNOR 0F (TYNE-HALF T0 HARRY A.

HIGGINS, 0F DETROIT, MICHIGAN. I

ART AND MEGHANISM FUR DWING HOLLOW CYLINDRIGAL METAL BODIEES.

inseam.

Specification of Letters Eatent.

Patented July is, 1922.

Application filed December 27, 1920. Serial No. 483,319.

To all whom it concern:

troit, county of Wayne, State of Michigan,

have invented a certain new and useful Improvement in the Art and Mechanism for Drawing Hollow Cylindrical Metal Bodies, and declare the following to be a full,'clear, and exact description of the same, such as will enable others skilled in theart to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates to the art of drawing hollow cylindrical metalbodes, commonly referred to as tubes ort shells, for the sake of convenience hereinafter referred .to as tubes, over a triblet or mandrel and particularly to the. removal of the drawn cylinder from the mandrel. It is desired, however, not to limit this process to what are commonly known in the trade as tubes.

My invention consists in the process of hammering or swaging the tube on the mandrel as on an anvil thereby expanding the tube so that the mandrel may be easily withdrawn therefrom and in the means provided for accomplishing such object. I

Figure 1 is an elevation of a drawing Fig. 2 is an enlarged plan view partly broken away.

Fig. 3 is a section taken on line 3-3,

Fig. 4 is a section taken on line t--4,

Fig. 5 is an elevation showing a triblet carrying a tube.

Fig. 6 is an elevation of a triblet showing the tube partly in section.

In the drawing of metal tubes over a mandrel the mandrel carrying the tube is drawn through a draw-plate of lesser diameter than the tube, the tube being thereby reduced in gauge and diameter and increased in length. There is nothing new in this method of drawing metal tubes. The disadvantage, however, lies in the difficulty of removing the mandrel from the drawn tube. My invention relates to an improved process for removing the mandrel from the tube. 1 expand the tube on the mandrel by hammering the tube throughout its length and shown in Fig.1 which chain may be driven by gearing as shown in Fig. 1. Separate links of this chain are adapted to be engaged by the hook of a reach-bar d. This reach-bar is secured to a carriage consisting of forward and rearward sectionse and 6 respectively which carriage is adapted to run back and forth in a provided runway 6 This carriage is provided with gripping jaws adapted to grip the end of a mandrel to draw thesame along with the movement of the carriage as shown in Fig. 2.

These jaws are indicated as f and f and are pivoted to.each other and to section 6 of the carriage at h. The forward end of each of these jaws is serrated providing a good gripping surface.v The end of each jaw opposite its gripping end is pivoted to section 0 of the carriage by means of a link 2'', such links being pivoted to each other and to such carriage section at g. A tongue is is secured to the section 6 of the carria e and pivotally connected with the reac bar d. I

At the head of the draw-bench is a draw plate am through which the tube is drawn to reduce its diameter and gauge.

When it is desired to draw-a'tube such as 0 a mandrel p is passed threrethrough. This mandrel is of less diameter at one end for a portion of its length than at the other and the sections of varying diameters are separated by a shoulder p as shown in Fig. 6. The portion of the mandrel of-larger diameter is of course of less diameter than the interior diameter of the tube to be drawn. The end of thetube has been previously pointed as at 0 to engage the shoulder of the mandrel. The smaller end of the mandrel which mandrel carries the tube as shown in Fig. 6 is now passed through an opening in thedrawplate and through the central opening in the revolve.

I) the movement of the chain will draw the mandrel and tube through the draw-plate m and through theswaging machine' The swaging or hammering device might be of any conventional form. As shown in the drawings, it comprises a housing 97. within which a rotating spindle r is adapted to A flywheel s is mounted on the spindle so as to drive the same. 7 is a bearing for the spindle within the housing. Supporting standards for the device are indicated as 8 The face of the spindle is slotted to receive a pair of dies trounded on their inner ends after the manner of peening hammers which dies are held between a pair of backers t Outside of and around the spindle is an annular rack 9 containing loosely a number of hardened steel rolls g which are separated from each other in individual pockets as indicated. The revolution of this spindle causes the dies and hackers to pass between successive pairs of opposing rolls which force the dies together. The spindle is hollow to permit the tube to be fed through it. The dies revolve rapidly around the tube 0 carried by the mandrel p while the rack containing the rolls revolves more slowly being moved only by the slight motion of the rolls during the time of contact with the backers. The dies are of hardened steel and they are adjustable as to projection by means of steel shims a which separate the die from its backers. n is a gateway plate carried by the housing. No claim is made to this swaging device as a tool, for with the exception of possibly the dies constructed in the manner of peening hammers, it,.is a well known form of swagin machine.-

uring the drawing process the mandrel and tube are drawn through the swaging device just after they'leave the draw-plate. The swaging device would necessarily be adapted for the particular diameter of tube drawn; As the mandrel and tube are drawn through the swaging device a multiplicity of hammer like blows or compression impulses are administered the exterior of the tube 1 ,aaaeva per minute. These hammer blows expand the tube so that after the tube is removed from the machine the mandrel can be easily withdrawn therefrom.

,What I claim is: I

1. In the art of drawing metal tubes over a mandrel, the method of removing the mandrel therefrom, which consists in hammering the tube on the mandrel so as to expand the tube in order that the mandrel may be withdrawn.

2; In the art of drawing metal tubes over a mandrel, the process of removing the mandrel from the tube which consists in hammering the tube throughout its length and circumference a sufficient number of times to cause expansion of the tube permitting the withdrawal of the mandrel.

3. In the art of drawing metal tubes over a mandrel, drawing a mandrel carrying a metal tube through a draw-plate so as to reduce the gauge and diameter of the tube and increase its length, and striking the outer surface of the tube a multiplicity of blows throughout its length and circumference so as to cause expansion of the tube permitting the withdrawal of the mandrel therefrom.

4:- In a metal tube drawing machine, a draw-plate, means for drawing a mandrel and tube therethrough means for hammering the tube on the mandrel as on an anvil as it moves along and after it leaves the drawplate.

5. In a metal tube drawing machine a draw-plate through which a mandrel carrying a tube may be drawn, a hammering device aligned with said draw-plate adapted to hammer the tube throughout its length and circumference as it is drawn along after it leaves the draw-plate.

CLIFFORD BL HIGGINS. 

